Hello,
Permissions on folder work on top-down, once you give access to a folder to a member he will have access to all subfolders. This is really not working because at the first level of folder you need to create as much folder as permissions combination you have, and the tree structure quickly starts to be rough and unreadale.
Could you change that, and have it done like on other platforms, All access are given at first level and access can be taken away at each subfolder levels. The best would be able to give access directly to the folder whatever the permissions to the father or child folder.
Thank you.